Impact of a Single-Day Lockdown on COVID-19: An Interrupted Time Series Analysis

This study evaluated a special form of lockdown that was applied in Jordan: one day of lockdown every week, which was applied on consecutive weekend days (i.e., Friday in Jordan, for 24 hours). We tried to assess the impact of this form of lockdown on the daily number of positive coronavirus disease 2019 (COVID-19) cases, using interrupted time series analysis. We included the period of March 5 to April 17, 2021, as the period affected by the Friday lockdown, which was applied to seven consecutive Fridays with a total of 168 hours. We used R version 4.0.5 (R Foundation for Statistical Computing, Vienna, Austria) for our analysis. We used Poisson model regression analysis, where the number of positive cases was used as the outcome variable, while the total number of tests, time, and lockdown were used as the predictor variables. We further performed quasi-Poisson regression analysis to confirm the first model. On Poisson model regression analysis, it was found that there was an evidence of an increase in the number of positive COVID-19 cases following the intervention of Friday lockdown, with a p value of <0.001 (relative risk, 1.569; 95% confidence interval, 1.549-1.590). On using quasi-Poisson regression, similar results were found with a wider confidence interval. We concluded that a single weekend day lockdown led to an increase in the number of daily cases of COVID-19. Therefore, we recommend authorities to adhere to evidence-based measures or to the WHO recommendations in the dealing with this pandemic.